The specific aims for this project are: (1) to comprehensively examine and describe common injury patterns, physical findings, and forensic biomarkers in a series of highly adjudicated cases of physical elder abuse using a mixed methods approach, (2) to conduct a case-control study comparing these injury patterns to those sustained by older adults after an accidental fall, and (3) to design a clinical decision rule to assist health care providers in identifying abuse victims. We will achieve these aims through a unique collaboration with the Elder Abuse Unit (EAU) of the Brooklyn District Attorney's Office. The Brooklyn EAU successfully prosecutes more than 100 cases of physical elder abuse annually and maintains comprehensive files including photographs of injuries, medical records, description of first responder interactions with victim and perpetrator, and court documents. We will closely examine 200 files to comprehensively describe injury patterns as well as characteristics of victims and abusers. This innovative design, using cases of indisputable physical elder abuse, represents an important methodologic advance, as previous research has suffered from insufficient access to a large number of well-characterized elder abuse cases. Given the challenges associated with differentiating elder abuse from accidental injury, we will compare results from these cases to a control group of geriatric patients presenting to the emergency department with accidental falls to identify injury patterns and biomarkers associated with abuse. Ultimately, we plan to derive a clinical decision rule that will assist health care providers in more effectively screening for elder abuse. The applicant, Dr. Anthony Rosen, is an Emergency Medicine physician who has demonstrated significant research and clinical interest in acute geriatric care. He has a successful track record of collaboration in elder maltreatment research with Dr. Mark Lachs, an established NIH-funded researcher, who serves as Geriatrics mentor and co-investigator. Dr. Stephen Hargarten, his Emergency Medicine mentor and a co-investigator, is a pioneer in academic Emergency Medicine and violence prevention research. Having completed an MPH in epidemiology, Dr. Rosen is already trained in research methods and biostatistics. He is a former recipient of the Medical Student Training in Aging Research (MSTAR) grant and has mentored multiple MSTAR student research projects. In addition to his faculty appointment, Dr. Rosen will pursue a Geriatric Emergency Medicine fellowship during the grant period to increase his expertise in caring for older adults. The study proposed can be feasibly completed in two years with the support provided through this R03, particularly because, through funding from his institution, Dr. Rosen will already have salary support for 75% time protected from clinical responsibilities, and all NIA funds awarded will be allocated exclusively to support this research. The long-term goal of this proposal is to develop, implement, and evaluate comprehensive strategies to improve identification and prevention of elder abuse by health care providers and to launch the academic career of a promising junior investigator.